Q: Is it lawful for an officer to falsify a code violation during a traffic stop?

A: No, it is not lawful for an officer to falsify a code violation during a traffic stop. Law enforcement officers must have legitimate probable cause or reasonable suspicion to initiate a traffic stop, and fabricating a violation constitutes misconduct that potentially violates your Fourth Amendment rights against unreasonable searches and seizures. The false claim about your tail light could invalidate the entire legal basis for the stop, search, and subsequent arrest.

Your situation suggests a possible "pretextual stop" — where officers use a minor (in this case, fabricated) violation to investigate unrelated criminal activity. Courts have consistently ruled that evidence obtained from unlawful stops can be thrown out under the "fruit of the poisonous tree" doctrine. The dashcam footage you mentioned could be crucial evidence in demonstrating that the initial reason for the stop was fabricated.

You should consider consulting with a criminal defense attorney immediately who can review the dashcam footage and help you challenge both the basis for the stop and the resulting evidence. Documentation is key, so write down everything you remember while it's fresh in your mind. You might also want to file a formal complaint with the police department's internal affairs division or civilian oversight board, though your attorney may advise on the best timing for this step in relation to your criminal case.